The observed vertical patterns of velocity ellipsoid help us to revisit the nature of the disk flaring. We find that the flaring of the disk begins near the solar position, which agrees with the findings of [1]}. The position where the flaring starts to manifests itself is not settled. For instance, [2]} found a strong flare beginning well inside \(R_0\)  based on 2MASS red clump giants. To the contrary, [3]} and [4]} found that the flare begins at \(R\gtrsim 10\,\mathrm {kpc}\)  by using samples of SDSS-SEGUE F8V-G5V stars and LAMOST OB stars respectively. In recent studies, the flaring of a disk has been detected not only for our home galaxy but also for the external galaxies ([5]}; [6]}; [7]}), which means that a flared disk could be a common structure in disk galaxies. The drivers of the formation of disk flaring is still unclear, one hypothesis is the minor mergers [8]}.
